reproduce (this is a W=1 build):
        git clone https://github.com/intel/lkp-tests.git ~/lkp-tests
        # https://github.com/krzk/linux/commit/b97538c00c8e24fc168f3addbe7eba146b06396b
        git remote add krzk-github https://github.com/krzk/linux
        git fetch --no-tags krzk-github b4/sm8750-dispcc
        git checkout b97538c00c8e24fc168f3addbe7eba146b06396b
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-14.2.0 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=s390 olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-14.2.0 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=s390 SHELL=/bin/bash